Treatment of hydrocarbons



Oct. 26, 1943. s. EGLOFF 'IREA'I'MEN'JJ OF HYDROCARBONS Filed Nov. 50, 1940 FRACTIONATOR INVENTOR G USTAV EGLOFF ATTORNEY Patented Oct. 26, 1943 TREATMENT or maocannous Gustav Eglofl, Chicago, 111., assignor to Universal Oil Products Company. Chicago, 111., a. corporation of Delaware Application November 30, 1940, Serial No. 368,032

- 9 Claims. (01. 260 683.4)

This invention relates to a process for producing a substantially saturated gasoline of high antiknock value from isoparaflinic hydrocarbons and a normallyv liquid olefin-containing hydrocarbon fraction. More specifically the invention is concerned with a process which comprises alkylation of normally gaseous and normally liquid isoparamnic hydrocarbons by olefins present in hydrocarbon fractions of gasoline boiling range produced by cracking, reforming, and polymerization.

' A hydrocarbon fraction containing a relatively high proportion of olefins such as a gasoline formed by thermal orcatalytic cracking or by other means is inferior 1or use as aviation fuel because of its high olefin content and its accom- .panyingtendency to oxidize and deposit gum during storage together with the fact that such an olefin-containing fuel has relatively lower antiknock value than is generally desired for aviation purposes. Generally, little improvement in 'antiknock value is effected by addition of lead tetraethyl to such an olefin-containing fuel. Ac-

cordingly it is the purpose of this invention to produce from olefin-containing hydrocarbon fractions and isoparaflinic hydrocarbons relatively high yields of substantially saturated motor fuel of high antiknock value suitable for use in I airplane and automobile engines. Further, the antiknock values of these fuels may be increased by moderate additions of lead tetraethyl.

In one specific embodiment the present invention comprises a process for producing a substantially saturated gasoline which comprises commingling an isoparaifinic hydrocarbon fraction with a metallic halide alkylating catalyst in a reactor coil; injecting into said coil at a plurality of points intermediate between its entrance and exit an olefin-containing gasoline and a relatively minor proportion of a hydrogen halide to form a substantially saturated product from isoparafiinic and,olefinic hydrocarbons; separating said product into alight fraction comprising essentially unconverted isoparaffinic hydrocarbons and hydrogen halide, a substantially saturated alkymer gasoline of high antiknock value, and a relatively heavy residue containing metallic halide alkylating catalyst; and recycling said light fraction to commingle with the mixture of isoparafiinic hydrocarbon fraction and metallic halide charged to the process.

A feature of the present invention is the addition of an olefin-containing hydrocarbon fraction at a plurality of points in the reaction coil through which is passed a metallic halide alkylating catalyst such as aluminum chloride and a molar excess of an isoparafiinic' hydrocarbon at a temperature of from about 0 to about 200 F. under a pressure of from substantially atmospheric to approximately 600 pounds per square inch. A hydrogen halide as hydrogen chloride is also 'added to the olefin-containing hydrocarbon fraction prior to im'ection into the mixture of isoparafiin hydrocarbons and metallic halide. Alkylationof isoparaifinwith olefins is promoted and undesirable polymerization is substantially avoided when the olefin-containing hydrocarbon fraction is so added at a plurality of points throughout the length of the alkylating reactor. The reaction may thusbe carried out so that from about 2- to about 40 molecular proportions of isoparafiin are commingled with each molecular proportion of olefin added thereto.

Addition of a hydrogen halide as hydrogen chloride to the reaction mixture in an amount of from between about 0.5 ,to about 15% by weight thereof not only promotes-the alkylating activity of the metallic halide catalyst but also tends to progressively restore alkylating activity to the used metallic halide catalyst as it passes through the alk ylating reactor. As the mixture of isoparafiins, olefins, and metallic halide catalyst enters the reactor, relatively little hydrogen halide is present, but as the reaction mixture continues in its pasage through the alkylating reactor the hydrogen halide concentration increases progressively. The resulting reaction productv is separated into a mixture of hydrogen halide and unconverted isoparaffins, a substantially saturated alkylate of gasoline boiling range, and a sludge or residue containing the metallic halide catalyst. t least a portion of said mixture of hydrogen halide and unconverted isoparaiiins is recycled to commingle with the mixture of freshly added isoparafiin hydrocarbons and metallic halide be- 7 ing charged to the alkylation reactor. After the process is in operation, the hydrogen halide which is continuously commingled with the charged olefin-containing fraction is suificient to replace the hydrogen halide lost from the system. The catalyst of the Friedel-Craft type employed which consists of a halide or a mixture of halides, preferably the chlorides, of aluminum, zinc, iron, zirconium, copper, etc., is used in an amount of from about 1 to about 15% by weight of the hydrocarbons present in the alkylating zone.

The difierent alkylating catalysts which may be used alternatively for promoting the" process of this invention are not necessarily equivalent in their action and the conditions of temperature,

pressure, and time employed in any given alkylation are determined by the catalyst, the composition of the reaction mixture, and by other factors.

For the purpose of illustrating the combination of steps characteristic of the present invention, the accompanying drawing illustrates diagrammatically means embodying one specific apparatus utilizable for producing gasoline of high antiknock value from isoparafiinic hydrocarbons and normally liquid olefin-containing fractions as may be produced bymracking, reforming, and

polymerization.

Referring to the drawing, a mixture of aluminum chloride and of an isoparaflin hydrocarbon or of an isoparaflin hydrocarbon fraction is introduced through line I and valve 2 to pump 3 which discharges through line 4 and valve 5 into coil 6 provided with jacket 1 through which a heating or cooling medium may be circulated by way of lines 8 and 9 in order to maintain an alkylating temperature in coil 6. Simultaneously and continuously an olefin-containing gasoline, such as may be formed by cracking, reforming, and polymerizing treatments, is admitted through line H) and valve H to pump l2 which discharges through header l3 containing valves H and i5. Hydrogen chloride from an. outside source is directed through line l6 and valve I! to pump or compressor I8 which discharges through line l9 and valve into header I3, ala chloride-isoparaflin mixture as already described.

The commingled mixture of olefin-containing hydrocarbon fractions and hydrogen chloride, the latter also present in at least a portion of header I3, is directed therefrom through branch lines and 26, provided respectively with valves 21 and 28, to coil 6, already mentioned. Header l3 also communicates with coil 6 through valve l5. As hereinabove set forth, the olefin-containing hydrocarbon fraction maybe introduced to the aluminum chloride-isoparaflin mixture in coil 5 at a plurality of points, indicated diagrammatically as 5 in the accompanying drawing, although any plurality of points of injection for olefin and hydrogen chloride may be employed. The hydrogen chloride and olefin-containing fraction may be introduced together or separately to the reaction coil.

From coil 6 the alkylation mixture which is substantially free from olefinic hydrocarbons is directed through valve 29 and line 30 to fraction ator 3| of conventional design adequate to separate a light fraction comprising essentially an unconverted hydrocarbon fraction and hydrogen chloride, a substantially saturated alkylate, and a residue or sludge containing aluminum chloride catalyst employed in the alkylation. While a major proportion of the alkylation reaction occurs during contact of the hydrocarbons with the catalyst in reactor 6, this conversion may reach completion in the lower portion of fractionator 3|, from the top of which a light fractioncomprising essentially an unconverted isoparaflln fraction and hydrogen chloride is directed through line 32 and valve 33 to pump 34 which discharges through line 35 and valve 36 into the entrance end of coil 6 employed as a reactor for alkylation of isoparaflln hydrocarbons with olefins. A portion of the light traction passing through line 32 is directed therefrom to waste, storage, or other use through line 31 and valve 38. The substantially saturated alkylate of high antiknock value is directed from fractionator 3! through line 39 containing valve 40 to cooling and storage, not shown in the diagrammatic drawing. The residue or sludge containing the aluminum chloride catalyst is withdrawn from the bottom of fractionator 3| through line 4| and valve 42 to storage or to other use, not shown. Also a portion of said sludge containing used aluminum chloride may be returned to coil 6 by means not shown to therein assist in the alkylation of isoparamns with olefins.

The following example is introduced to show results normally expected in the operation of the process although with no intention of unduly 1ltiimiting the generally broad scope of the inven- 5 molecular proportions of isobutane having dispersed therein about 10% by weight of finely divided anhydrous aluminum chloride is passed through a reaction coil maintained at 150 F., to which is added one molecular proportion of a cracked gasoline containing approximately 30% by weight of normally liquid olefins. The cracked gasoline is commingled with about 4% by weight of hydrogen chloride and the resulting mixture is introduced at different points in said reaction coil intermediate between its entrance and exit ends in order to catalyze alkylation and to substantially avoid polymerization of olefins contained in said gasoline. The alkylation of isobutane by the normally liquid olefins present in said cracked gasoline converts said olefins and a portion of the added isobutane into a substantially saturated alkylate recoverable in admixture with the saturated constituents of the cracked gasoline charged. Thus the total yield of substantially saturated motor fuel is approximately 125% by weight of the cracked gasoline charged to the process.

The character of the present invention and its novelty and utility in producing substantially saturated motor fuel from olefin-containing gasoline and added isoparaflin hydrocarbons can be seen from the preceding specification and example given, although neither section is intended to limit unduly the generally broad scope of the process.

I claim as my invention:

1. A process for producing a substantially saturated gasoline which comprises commingling an isoparaflinic hydrocarbon fraction with a metallic halide alkylating catalyst in a reactor coil; injecting into said coil at a plurality of points intermediate between its entrance and exit ends an olefin-containing gasoline and a relatively minor proportion of a hydrogen halide to form a substantially saturated product; separating said product into a light fraction comprising essentially unconverted isoparafilnic hydrocarbons and hydrogen halide, a substantially saturated alkymer gasoline of high antiknock value, and a relatively heavy residue containing metallic halide alkylating catalyst; and recycling said light fractlon to commingle with the mixture of isoparaf finic hydrocarbon fraction and metallic halide charged to the process.

2. A process for producing a substantially saturated gasoline which comprises commingling an gasoline and a relatively minor proportion of hydrogen chloride to form a substantially saturated product; separating said product into a light fraction comprising essentially unconverted isoparaffinic hydrocarbons and hydrogen chloride, a substantially saturated alkymer gasoline of high antiknock value, and a relatively heavy residue containing alum num chloride: and recycling said light fraction to commingle with the mixture of isoparaflinic hydrocarbon fraction and aluminum chloride charged to the process.

3. A process for producing a substantially saturated gasoline which comprises commingling an isoparaflinic hydrocarbon fraction with aluminum'chloride and another metal chloride of the Friedel-Crafts type in a reactor coil; injecting into said coil at a plurality of points intermediate between its entrance and exit ends an olefincontaining gasolin and a relativelyminor proportion of hydrogen chloride to form a substantially saturated product; separating said product into a light fraction comprising essentially unconverted isoparaflinic hydrocarbons and hydrogen chloride, a substantially saturated alkymer gasoline of high antiknock value,'and a relatively heavy residue containing the metallic chloride alkylating catalyst mixture; and recycling said light fraction to commingle with the mixture of isoparafiinic hydrocarbon fraction and metallic chlorides charged to the process.

4. A process for producing a substantially saturated gasoline which comprises commingling an isoparafllnic hydrocarbon fraction with alnmi-- num chloride and another metal chlorideof the Friedel-Crafts type in a reactor coil maintained at a temperature between about and about 200 F., injecting into said coil at a plurality of points intermediate between its entrance and exit ends an olefin-containing gasoline and a relatively minor proportion of hydrogen chloride to form a substantially saturated product; separating said product into a light fraction comprising essentially unconverted isoparafllnic hydrocarbons and chloride in a reactor coil; injecting into said coil at a plurality of points intermediate between its entrance and exit ends an olefin-containing gasoline and between about 0.5 and about by weight of hydrogen chloride to form a substantially saturated product; separating ,said product into a light fraction comprising essentially unconverted isoparaflinic hydrocarbons and hydrogen chloride, a substantially saturated alkymer asoline of high antilmock value, and a relatively heavy residue containing aluminum chloride; and recycling said light fraction to commingle with the mixture of isoparafiinic hydrocarbon fraction and aluminum chloride charged to the process. 7. A process for producing a substantially saturated gasoline which comprises commingling an isoparahlnic hydrocarbon fraction with between about 1% and about 15% by weight of a mixture of aluminum chloride and another metal chloride of the Friedel-Crafts type in a reactor coil maintained at a temperature between about 0 and about 200 F.; injecting into said coil at a plurality of points intermediate between its entrance and exit ends an olefin-containing gasoline and between about 0.5 and about 15% by weight'of hydrogen chloride to form a substantially saturated product; separating said product into a light fraction comprising essentially unconverted isoparaifinic hydrocarbons and hydrogen chloride,

a substantially saturated alkymer gasoline of high antiknockvalue, and a relatively heavy residue containing the metallic chloride alkylating catalyst mixture; and recycling said light fraction to commingle with the mixture of isoparafiinic hydrocarbon fraction and metallic chlorides charged to the process.

8. A process for producing a substantially saturated gasoline which comprises commingling hydrogen chloride, a substantially saturated al- Y kymer gasoline of high antiknock value, and a relatively heavy residue containing th metallic chloride alkylating catalyst mixture; and recycling said light fraction to commingle with the mixture of isoparafllnic hydrocarbon fraction and metallic chlorides charged to the process.

5. A process for producing a substantially saturated gasoline which comprises commingling an isoparaihnic hydrocarbon fraction with between about 1% and about 15% by weight or aluminum chloride in a reactor coil; injecting into said coil at a plurality of points intermediate between its entrance and exit ends an olefin-containing gasoline and a relatively minor proportion of hydrogen chloride to form a substantially saturated product; separating said product into a light trac- 60 tion comprising essentially unconverted isoparatflnic hydrocarbons and hydrogen chloride, 8. substantially saturated alkymer gasoline of high antiknock value, and a relatively heavy residue containing aluminum chloride; and recyclin said light fraction to commingle with the mixture of isoparafllnic hydrocarbon fraction and aluminum chloride charged to the process. 1

6. A process for producing a substantially saturated gasoline which comprises commingling an isoparamnic hydrocarbon fraction with between about 1% and about 15% by weight or aluminum the eflluent of said zone to separate gasoline frac- I between about 2 and about 40 molecular proportions of an isoparaflinic hydrocarbon fraction with between about 1% and about 15% by weight of aluminum chloride in a reactor coil; injecting into said coil at a plurality of points intermediate between its entrance and exit ends from about 0.5 to about 15% by weight of hydrogen chloride based upon the isoparaflinic hydrocarbons and a gasoline containing about 1 molecular proportion of olefinic hydrocarbons to form a substatiaily saturated product; separating said product into a light fraction comprising essentially unconverted isoparailinic hydrocarbons and hydrogen chloride, a substantially saturated alkymer gasoline of high antiknock value, and a relatively heavy residue containing aluminum chloride; and recycling said light fraction and at least a portion of said heavy residue containing aluminum chloride to commingle with the mixtureof isoparafilnic hydrocarbon fraction and aluminum chloride charged to the process.

9. A process for producing substantially sat-.

urated gasoline which comprises commingling a low "boiling isoparafllnic' fraction with a metal halide alkylating catalyst, passing the resultant mixture in a restricted stream through a reaction zone maintained under alkylating conditions, introducing-to said stream at a plurality of spaced points in its path of travel through the reaction zone a hydrogen halide and oleflnic hydrocarbons,

boiling inthe gasoline range. and fractionating tions therefrom.

GUSTAV EGIDFF. 

